| Abstract: | Since the inception of Operation Gatekeeper along the U.S.–Mexico border, there has been an increase in environmental impacts on the Cleveland National Forest, in eastern San Diego County, California. This is almost certainly due to an increase in the number of undocumented immigrants using the area as a gateway to the interior of the United States. In this research, we use the tools of geographic information systems (GIS) to measure the scope and extent of this impact, focusing on the creation of illegal trails and the impact of illegal campsites and campfires on the environment of the Descanso Ranger District within the national forest. Our findings suggest that between the start of Operation Gatekeeper in late 1994 and the end of the study period in 1999, there were 772 meters of new trail created per 1,000 unauthorized immigrants, accompanied by 656 square meters of area disturbed per 1,000 immigrants, fifty kilograms of litter left behind per 1,000 immigrants, eleven illegal campfires per 1,000 immigrants, and 1.7 hectares burned by wildfires attributed to illegal immigrants. |
